Objective: To investigate whether symptoms of fatigue are significant predictors of neurocognitive outcomes. Design: Retrospective analysis of clinical data. Setting: Clinical patients presenting to an outpatient clinic for neuropsychological evaluation following mild traumatic brain injury (mTBI). Subjects: 55 participants (33 male; 69% white, 18% African American) aged 11–18 years diagnosed with mTBI: 78% resulting from sport participation, 38% reporting loss of consciousness, 34% retrograde amnesia and 58% anterograde amnesia; 30% with at least one previous concussion. Pre-injury history: headache (14%), attention deficit hyperactivity disorder (ADHD; 18%), learning disability (14%), depression (14%) and anxiety (10%). Current medications: 25% over-the-counter pain medication, 12% stimulant and 10% antidepressant. Intervention: Parents completed rating scales of fatigue and children received neurocognitive evaluation including ImPACT. Outcome Measures: Fatigue was measured by the PedsQL 4.0 multidimensional fatigue scale for current symptoms and preinjury. The PedsQL contains 18 items in three fatigue indexes (ie, general, sleep/rest and cognitive). Four composite ImPACT scores (ie, verbal memory, visual memory, processing speed and reaction time) served as neurocognitive measures. Results: Repeated measures analysis revealed significant improvement in fatigue symptoms and cognitive performance across three appointments. Multivariate linear regression analyses were performed to predict cognitive performance at three post-injury follow-up points. Bivariate correlation coefficients were first examined resulting in entrance of significant history variables (ie, number of previous concussions, history of ADHD and anxiety) and injury characteristics (ie, retrograde amnesia) first, followed by fatigue symptoms (general fatigue, sleep/rest fatigue and cognitive fatigue) to understand the unique contribution of fatigue to each cognitive outcome. Baseline sleep problems and gender were covariates. The results of the analyses for the three follow-up points indicated that none of the fatigue symptoms were significant predictors of cognitive performance. Retrograde amnesia and history of ADHD and anxiety were significant predictors. Conclusions: Although significant fatigue symptoms were reported post-mTBI, they were not found to predict neurocognitive outcome.